About Us....

Our extensive credentialing experience comes along with our fresh, new approach to much needed customer service in our industry. The culture of our company is professional yet easily approachable and accessible, knowledgeable and experienced, yet eager to meet any potential challenge of each unique client.

Tammy White, CPCS, CPMSM – President

With over 25 years of Primary Source credentialing experience, Tammy also holds an active CPCS & CPMSM Certification and active memberships in both NAMSS and CAMSS Associations. Tammy remains very involved in the Credentialing community to ensure Gemini clients are kept up-to-date on regulatory requirements, health plan standards, CMS changes, and more. Tammy has facilitated over 20 NCQA surveys, 2 URAC surveys and on-going support to clients through Joint Commission surveys. She holds a Bachelor’s Degree in Business Management and is a co-owner of Gemini Diversified Services, Inc.

Craig Rizzi – CEO

With over 13 years experience building a career around Credentialing, Provider Relations, and Contracting, Craig has focused his expertise on the development of several credentialing programs, building of provider networks, development of Provider education seminars within several major healthcare organizations.  Craig has led activities and served as an advisor on several multi-disciplinary contracts and credentialing committees.

GDS Staff

Knowledgeable, experienced staff is proud to service GDS clients.  With backgrounds working for health plans, hospitals, medical groups and CVO’s, GDS staff knows our line of business and they know it well.  A Certified Professional Credentialing Specialist (CPCS) is always on staff and available to you at all times .


GDS takes every precaution, utilizing state of the art technology to ensure our network is secure, reliable, and protected.   Data is secured to ensure confidentiality, HIPAA compliance and disaster recovery.

We utilize Cactus Software for tracking data and primary source verifications, reporting, and efficient facilitation of verification collection.  We offer clients access to their provider data through our internet based web module iObserver.  Clients may view provider data fields, see when verifications were requested and received, and download or print scanned images.

GDS responsibly utilizes a document scanning, paperless approach, which reduces environmental burdens and allows us to transfer documents more efficiently.